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You repeatedly receive a prompt for credentials in Outlook 2002 when you log on to the e-mail server

View products that this article applies to.


If you connect to Microsoft Exchange 5.5 or Microsoft Exchange 2000 to send or receive messages, you are repeatedly prompted for credentials and do not receive an error message. If you attempt to authenticate to the server through Telnet, the following error message may occur:
Task 'lima - Sending' reported error (0x800CCC0F) : 'The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP). The server responded: 454 5.7.3 Client was not authenticated.'

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This problem occurs because the Internet Mail Connector on the Exchange server has been set to only allow Integrated Windows Authentication or Secure Password Authentication.

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Use the following steps to resolve this problem:
  1. Start Outlook.
  2. On the Tools menu, click E-mail Accounts.
  3. In the E-mail Accounts dialog box, click View or change the existing e-mail accounts, and then click Next.
  4. Click the account that you want to change, and then click Change.
  5. Under Logon Information, click Log on using Secure Password Authentication (SPA).
  6. Click Next, and then click Finish.

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Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

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More information

For additional information about security settings on the Internet Mail connector in Exchange 5.0, 5.5 and 2000, click the article number below to view the article in the Microsoft Knowledge Base:
200788 XFOR: POP3 or IMAP4 Client Cannot Send SMTP Mail

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Keywords: KB297781, kbbug, kbemail, kberrmsg

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Article Info
Article ID : 297781
Revision : 6
Created on : 2/19/2007
Published on : 2/19/2007
Exists online : False
Views : 370